shotleybuilder

shotleybuilder

Exploring Graphs with Elixir: service contexts p.92-93

The book states “define the function graph_service/0 within the body of the using/1 macro
in the GraphCommons.Graph module”

The code download shows this:

defmacro using(opts) do
graph_type = Keyword.get(opts, :graph_type)
graph_module = Keyword.get(opts, :graph_module)

quote do

  # other (listings, new_graph) functions here

  def read_graph(graph_file),
    do: GraphCommons.Graph.read_graph(graph_file, unquote(graph_type))

  def write_graph(graph_data, graph_file),
    do: GraphCommons.Graph.write_graph(graph_data, graph_file,
    unquote(graph_type))
end

end

def graph_service(), do: unquote(graph_module)

def gs() do
graph_service()
graph_info()
end

I’ve not been able to work through the error here and obtain the result shown in the book, namely:

iex> graph_service PropertyGraph
PropertyGraph

So, no solution from me, but I sense there’s more than a one problem here

First Post!

shotleybuilder

shotleybuilder

Okay, this was simply a case of moving
def graph_service(), do: unquote(graph_module)
into the macro.

The error is in the code download

Where Next?

Popular Pragmatic Bookshelf topics Top

New
Alexandr
Hi everyone! There is an error on the page 71 in the book “Programming machine learning from coding to depp learning” P. Perrotta. You c...
New
simonpeter
When I try the command to create a pair of migration files I get an error. user=> (create-migration "guestbook") Execution error (Ill...
New
raul
Hi Travis! Thank you for the cool book! :slight_smile: I made a list of issues and thought I could post them chapter by chapter. I’m rev...
New
jskubick
I think I might have found a problem involving SwitchCompat, thumbTint, and trackTint. As entered, the SwitchCompat changes color to hol...
New
adamwoolhether
I’m not quite sure what’s going on here, but I’m unable to have to containers successfully complete the Readiness/Liveness checks. I’m im...
New
oaklandgit
Hi, I completed chapter 6 but am getting the following error when running: thread 'main' panicked at 'Failed to load texture: IoError(O...
New
taguniversalmachine
It seems the second code snippet is missing the code to set the current_user: current_user: Accounts.get_user_by_session_token(session["...
New
jonmac
The allprojects block listed on page 245 produces the following error when syncing gradle: “org.gradle.api.GradleScriptException: A prob...
New
dachristenson
I just bought this book to learn about Android development, and I’m already running into a major issue in Ch. 1, p. 20: “Update activity...
New

Other popular topics Top

PragmaticBookshelf
Stop developing web apps with yesterday’s tools. Today, developers are increasingly adopting Clojure as a web-development platform. See f...
New
PragmaticBookshelf
From finance to artificial intelligence, genetic algorithms are a powerful tool with a wide array of applications. But you don't need an ...
New
Exadra37
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
PragmaticBookshelf
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
New
PragmaticBookshelf
Author Spotlight: VM Brasseur @vmbrasseur We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
New
PragmaticBookshelf
Programming Ruby is the most complete book on Ruby, covering both the language itself and the standard library as well as commonly used t...
New
DevotionGeo
I have always used antique keyboards like Cherry MX 1800 or Cherry MX 8100 and almost always have modified the switches in some way, like...
New
PragmaticBookshelf
Develop, deploy, and debug BEAM applications using BEAMOps: a new paradigm that focuses on scalability, fault tolerance, and owning each ...
New
PragmaticBookshelf
A concise guide to MySQL 9 database administration, covering fundamental concepts, techniques, and best practices. Neil Smyth MySQL...
New

Sub Categories: